Site conservation

By its very nature, archaeology is destructive and irreversible. Site conservation, on the contrary, is concerned with preventing damage and slowing deterioration processes by using reversible methods. Despite this, at first glance, conflicting interest and objective, the preservation of the remains of the past has become an integral and mandatory part of the archaeological process as prescribed by international legal tools and national laws since the last century. These legal documents provide guidelines to avoid further destruction due to badly planned conservation choices.

The Sissi Archaeological Project puts an emphasis on respecting those guidelines while ensuring that professionals from both archaeology and conservation disciplines work alongside to preserve and, ultimately, present the site to both the scientific world and the general public.

A site at risks

Archaeology is a transformative activity. Indeed, archaeologists need to dig through different stratigraphic layers in order to unearth, record and interpret remains left by past behaviour. Ironically, a proper understanding of archaeological data brings along the destruction of their context and of their protective natural cover, thus disrupting the physico-chemical equilibrium of the environment in which these remains were maintained for centuries/millennia and exposing them to a new hostile natural and human environment.

In Sissi, the main natural factors threatening the remains are a result of the proximity of the site to the coastline. Indeed, strong winds and sea water splash foster a faster erosion of the unearthed archaeological remains. This particular location not only causes damage to the ruins but also to the modern protective installations: the metallic fence surrounding the site is constantly suffering from corrosion and needs continuous care. Moreover, the punctual sea water splash causes some excavated rooms to be flooded during the winter, acerbated by heavy rainwater fall and occasional very rough seas. This high moisture level hence turns the original earth binder of the walls into mud, causing lateral thrusts and the drift of masonry. It also stimulates vegetation growth (fig. 1)

Human action, other than that by the archaeologists, also put a strain on the conservation of the site. Indeed, despite the protective fence and prohibitive signs, both locals and tourists occasionally trespass, the first ones mainly in search of herbs and plants, the second using the site as a shortcut to reach the sandy beach on the eastern side of the Kephali hill. This sometimes leads to minor acts of vandalism (fig. 2).

These different threats converge to speed up the natural erosion of the remains. One of the most serious problems encountered, however, is the loss of cohesiveness of the original wall materials due to the loosening of the original earthen binder. This threatens the overall stability of the rubble structure, bringing along a danger of collapse. This risk is also the result of the vegetation growth on top of and inside the masonry engendering pressure on it (fig. 3).

To mitigate these deterioration processes, at the end of every summer campaign, the site is provisionally reburied or “back-filled”. This preventive and temporary conservation method is aimed at re-establishing a stable environment, similar to that which existed prior to the exposure of the remains, to minimize fluctuation in temperature and humidity while protecting the remains from the direct effects of water, wind, vegetation, light, animals and humans. It does not entirely stop the deterioration process but it significantly slows it down. The technique consists in layering down a layer of geotextile over walls, floors and other features and fill the space with earth, derived for practical, economical and conservation reasons, from the original excavation. The geotextile is used to discourage the growth of roots and as a way to separate the archaeological level from the reburied earth so that it can be easily distinguished and removed (fig. 4)

From the start of the excavations, large scale conservation work has taken place on the Kephali hill in order to durably protect the exposed remains from weathering while allowing their visibility (which the back-filling does not). The intervention mainly consist in the consolidation of the exposed masonry through mortar repointing and in the reinforcement of plaster on walls and floors using injection of a very sparse dissolution of acrylic resin (fig. 5). These interventions were first implemented in the field by the technician Nearchos Nikakis under the supervision and guidance of Alexandros Nikakis, former conservator of the ΚΔ’ Ephorate of Classical and Prehistoric Antiquities.

At the end of the first five-year cycle excavation campaign, all archaeological floors were covered, this time using a special gravel on top of the bulk fill separated from the archaeological level by geotextile.

During the study campaigns (2012-2014), we were able to observe that the mortar composition experimentally applied in the wall consolidation before was not entirely satisfactory since certain traces of decay (voids, cracks) were visible. Following the recommendation of Dr. Stephania Chlouveraki’s of the W.D.E. Coulson Conservation Laboratory of the Institute for Aegean Prehistory Study Center for East Crete and now chief conservator of our project, in close association with Dr. E. Toumbakari of the Ministry of Culture, an earth-based mortar which uses a mixture of white Portland cement, quarry sand and sieved soil derived from our excavation has been implemented. This type of mortar has the benefit of not only being physically but also aesthetically and historically compatible with the original earth fabric. It has already been widely tested at several sites on Crete (e.g. Mochlos, Azoria) and in the Cyclades. The experimental study of its properties and performance is still in progress (fig. 5).

This is now applied by our conservation team under direction of Dr. Chlouveraki, who employs a team of skilled technicians from the site of Azoria, rewarded by the AIA for their work, graciously sent by our colleague Donald Haggis. In 2016, they started the consolidation of walls of building CD and of the court-centred building (fig.7) and this will continue in the years to come.

While consolidation and site embellishment work will continue alongside excavation and study, we are also working on the design of a management plan for the site to allow its long-term and sustainable preservation and presentation to the public. Our goal is to provide visitors with the most “authentic” experience of a Minoan settlement. The basis for such a master plan is part of an ongoing PhD project by Thérèse Claeys at the Université catholique de Louvain. Its aim is to integrate local communities in the management of their heritage. By encouraging community ownership of the site, it seeks to ensure the site upkeep and maintenance while turning it into a catalyst to stimulate local economic development. As a first step towards the creation of a visitor circuit punctuated with information panels and appropriate visitor amenities such as benches, shaded rest areas or wayside viewing platforms, a temporary circulation scheme has already been implemented on the site. Vegetation has been cleared and stones alignments created to delimit a path which can easily be removed but offers a way to see the most important remains without intruding (fig. 8).

The intention behind the design of these paths is to ensure the safety of the ruins by keeping visitors at a certain distance from them while still offering a good view on the remains. Every summer, during the archaeological campaign, visitors are thus already welcomed to come and see by themselves the results of the excavations. They can even be given an exclusive guided tour …